local mmi, mma = math.min, math.max
local mfl = math.floor

local function comp(a, b)
  return a < b
end

local function lower_bound(ary, x)
  local num = #ary
  if num == 0 then return 1 end
  if not comp(ary[1], x) then return 1 end
  if comp(ary[num], x) then return num + 1 end
  local min, max = 1, num
  while 1 < max - min do
    local mid = mfl((min + max) / 2)
    if comp(ary[mid], x) then
      min = mid
    else
      max = mid
    end
  end
  return max
end

local n, k = io.read("*n", "*n", "*l")
local w, len, c = {}, {}, {}
for i = 1, n do
  local s = io.read()
  local wi, ci = s:match("(%w+) (%d+)")
  w[i] = wi
  len[i] = #wi
  c[i] = tonumber(ci)
end
local wj, wo, wi = {}, {}, {}
for i = 1, n do
  wj[i] = {}
  local cj = 0
  for j = 1, #w[i] do
    if w[i]:sub(j, j) == "J" then
      cj = cj + 1
    end
    wj[i][j] = cj
  end
  wo[i] = {}
  local co = 0
  for j = 1, #w[i] do
    if w[i]:sub(j, j) == "O" then
      co = co + 1
    end
    wo[i][j] = co
  end
  wi[i] = {}
  local ci = 0
  for j = 1, #w[i] do
    if w[i]:sub(j, j) == "I" then
      ci = ci + 1
    end
    wi[i][j] = ci
  end
end

local t = {}
local edge = {}
for i = 1, k * 3 + 1 do
  edge[i] = {}
  t[i] = -1
end
for i_n = 1, n do
  for j = 1, k * 3 do
    local step = 0
    local need_j = mma(0, k + 1 - j)
    local need_o = mma(0, mmi(k, 2 * k + 1 - j))
    local need_i = mmi(k, 3 * k + 1 - j)
    local offset = 0
    if 0 < need_j then
      local pos = lower_bound(wj[i_n], need_j)
      if len[i_n] < pos then
        step = wj[i_n][len[i_n]]
      else
        step = need_j
      end
      offset = pos
    end
    if offset <= len[i_n] then
      if 0 < need_o then
        local ofst_o = offset == 0 and 0 or wo[i_n][offset]
        local pos = lower_bound(wo[i_n], need_o + ofst_o)
        if len[i_n] < pos then
          step = step + wo[i_n][len[i_n]] - ofst_o
        else
          step = step + need_o
        end
        offset = pos
      end
    end
    if offset <= len[i_n] then
      if 0 < need_i then
        local ofst_i = offset == 0 and 0 or wi[i_n][offset]
        local pos = lower_bound(wi[i_n], need_i + ofst_i)
        if len[i_n] < pos then
          step = step + wi[i_n][len[i_n]] - ofst_i
        else
          step = step + need_i
        end
        offset = pos
      end
    end
    if 0 < step then
      if edge[j][j + step] then
        edge[j][j + step] = mmi(edge[j][j + step], c[i_n])
      else
        edge[j][j + step] = c[i_n]
      end
    end
  end--j
end--i_n
t[1] = 0
for i = 1, 3 * k do
  local srccost = t[i]
  if 0 <= srccost then
    for dst, cost in pairs(edge[i]) do
      if t[dst] == -1 then
        t[dst] = srccost + cost
      else
        t[dst] = mmi(t[dst], srccost + cost)
      end
    end
  end
end
print(t[3 * k + 1])